Conventionally, image display apparatuses such as projectors have been widely used. For example, light from light sources is modulated by a light modulator such as a liquid-crystal device and the modulated light is projected to a screen or the like, such that an image is displayed. Mercury-vapor lamps, xenon lamps, LEDs (Light Emitting Diodes), LDs (Laser Diodes), and the like are used as the light sources.
Patent Literature 1 has disclosed a projector including three or more light sources for brightening a projected image. In this projector, a pyramid-shaped reflection member is arranged at the center of a plurality of lamps. The number of sides of the pyramid-shaped reflection member corresponds to the number of lamps (light sources). Then, illumination light emitted from each lamp is reflected in the direction of a light modulation device by the corresponding side of the reflection member. Accordingly, it is possible to convert the illumination light from each light source into parallel light having many overlapping parts of light fluxes, and reduce the light amount loss. Further, even in the case where the number of lamps is increased, it is possible to prevent an optical system from being increased in size because the number of sides of the reflection member only needs to be increased (paragraphs 0038 to 0040 of the specification of Patent Literature 1).